The gene in the human body which carries the genetic information responsible for the synthesis of gamma-interferon contains certain sequences of bases which code for the amino acid sequence of gamma-interferon (exons) and certain sequences which do not code for gamma-interferon (introns). In a human cell, the gamma-interferon gene creates RNA in the nucleus of the cell. This RNA contains both introns and exons. The introns, which do not code for a sequence of the gamma-interferon, are deleted to generate messenger RNA (mRNA). After the introns are deleted, the resulting mRNA directs the synthesis of natural gamma-interferon in the cytoplasm of the cell.
The amino acid sequence of human gamma-interferon has been identified, and DNA which codes for the gamma-interferon has been incorporated into, for example, E. coli which is capable of producing the gamma-interferon (See, European Patent Application Publication No. 0077670, published on 27 Apr. 1983).